The development of mobile telephone technology raises a higher requirement on the performance test technology of mobile phone antenna. The present performance test technology of the mobile phone antenna do not consider how to test the performance of a mobile phone antenna in a real talking condition of a mobile phone, i.e. in a condition where “human” factors, for example, a mobile phone gets close to a human head or the head, neck, shoulder and etc. of a human body, are involved. The first step to solve the problem is to determine the performance test condition of the mobile phone antenna in the real talking condition, wherein the first condition is to determine the minimum measurement distance of a mobile phone antenna.